Abstract: The Hall Coefficient (HC) and the Magnetoresistance (MR) have been studied in two-dimensional systems. The HC and the MR in Rectangular Quantum Wire (RQW) subjected to a crossed DC electric field and magnetic field in the presence of a Strong Electromagnetic Wave (EMW) characterized by electric field are studied in this work. Using the quantum kinetic equation for electrons interacting with optical phonons, we obtain the analytic expressions for the HC and the MR with a dependence on magnetic field, EMW frequency, temperatures of systems and the length characteristic parameters of RQW. These expressions are different from those obtained for bulk semiconductors and cylindrical quantum wires. The analytical results are applied to GaAs/GaAs/Al. For this material, MR depends on the ratio of the EMW frequency to the cyclotron frequency. Indeed, MR reaches a minimum at the ratio 5/4, and when this ratio increases, it tends towards a saturation value. The HC can take negative or positive values. Each curve has one maximum and one minimum. When magnetic field increases, the HC is negative, achieves a minimum value and then increases suddenly to a maximum with a positive value. This phenomenon differs from the one observed in cylindrical quantum wire, which does not have maximum and minimum values.
Abstract: An analysis of the air tightness level is performed on a representative sample of school classrooms in Southern Spain, which allows knowing the infiltration level of these classrooms, mainly through its envelope, which can affect both energy demand and occupant's thermal comfort. By using a pressurization/depressurization equipment (Blower-Door test), a characterization of 45 multipurpose classrooms have been performed in nine non-university educational institutions of the main climate zones of Southern Spain. In spite of having two doors and a high ratio between glass surface and outer surface, it is possible to see in these classrooms that there is an adequate level of airtightness, since all the n50 values obtained are lower than 9.0 ACH, with an average value around 7.0 ACH.
Abstract: The aim of irrigation is to recharge the available water
in the soil. Quality of irrigation water is essential for the yield and
quality of crops produced, maintenance of soil productivity and
protection of the environment. The analysis of irrigation water arises
as a need to know the impact of irrigation water on the yield of crops,
the effect, and the necessary control measures to rectify the effect of
this for optimum production and yield of crops. This study was conducted to assess the quality of irrigation water
with its performance on crop planted, in Josepdam irrigation scheme
Bacita, Nigeria. Field visits were undertaken to identify and locate
water supply sources and collect water samples from these sources;
X1 Drain, Oshin, River Niger loop and Ndafa. Laboratory
experiments were then undertaken to determine the quality of raw
water from these sources. The analysis was carried for various parameters namely; physical
and chemical analyses after water samples have been taken from four
sources. The samples were tested in laboratory. Results showed that
the raw water sources shows no salinity tendencies with SAR values
less than 1me/l and Ecvaules at Zero while the pH were within the
recommended range by FAO, there are increase in potassium and
sulphate content contamination in three of the location. From this, it
is recommended that there should be proper monitoring of the
scheme by conducting analysis of water and soil in the environment,
preferable test should be carried out at least one year to cover the
impact of seasonal variations and to determine the physical and
chemical analysis of the water used for irrigation at the scheme.
Abstract: With the strengthened regulation on the mandatory use
of recycled aggregate, development of construction materials using
recycled aggregate has recently increased. This study aimed to secure
the performance of asphalt concrete mixture by developing
recycled-modified asphalt using recycled basalt aggregate from the
Jeju area. The strength of the basalt aggregate from the Jeju area used
in this study was similar to that of general aggregate, while the specific
surface area was larger due to the development of pores. Modified
asphalt was developed using a general aggregate-recycled aggregate
ratio of 7:3, and the results indicated that the Marshall stability
increased by 27% compared to that of asphalt concrete mixture using
only general aggregate, and the flow values showed similar levels.
Also, the indirect tensile strength increased by 79%, and the toughness
increased by more than 100%. In addition, the TSR for examining
moisture resistance was 0.95 indicating that the reduction in the
indirect tensile strength due to moisture was very low (5% level), and
the developed recycled-modified asphalt could satisfy all the quality
standards of asphalt concrete mixture.
Abstract: Fractal based digital image compression is a specific
technique in the field of color image. The method is best suited for
irregular shape of image like snow bobs, clouds, flame of fire; tree
leaves images, depending on the fact that parts of an image often
resemble with other parts of the same image. This technique has
drawn much attention in recent years because of very high
compression ratio that can be achieved. Hybrid scheme incorporating
fractal compression and speedup techniques have achieved high
compression ratio compared to pure fractal compression. Fractal
image compression is a lossy compression method in which selfsimilarity
nature of an image is used. This technique provides high
compression ratio, less encoding time and fart decoding process. In
this paper, fractal compression with quad tree and DCT is proposed
to compress the color image. The proposed hybrid schemes require
four phases to compress the color image. First: the image is
segmented and Discrete Cosine Transform is applied to each block of
the segmented image. Second: the block values are scanned in a
zigzag manner to prevent zero co-efficient. Third: the resulting image
is partitioned as fractals by quadtree approach. Fourth: the image is
compressed using Run length encoding technique.
Abstract: An Energetic and exergetic analysis is conducted on a
Steam Turbine Power Plant of an existing Phosphoric Acid Factory.
The heat recovery systems used in different parts of the plant are also
considered in the analysis. Mass, thermal and exergy balances are
established on the main compounds of the factory. A numerical code
is established using EES software to perform the calculations
required for the thermal and exergy plant analysis. The effects of the
key operating parameters such as steam pressure and temperature,
mass flow rate as well as seawater temperature, on the cycle
performances are investigated. A maximum Exergy Loss Rate of about 72% is obtained for the
melters, followed by the condensers, heat exchangers and the pumps.
The heat exchangers used in the phosphoric acid unit present
exergetic efficiencies around 33% while 60% to 72% are obtained for
steam turbines and blower. For the explored ranges of HP steam
temperature and pressure, the exergy efficiencies of steam turbine
generators STGI and STGII increase of about 2.5% and 5.4%
respectively. In the same way optimum HP steam flow rate values,
leading to the maximum exergy efficiencies are defined.
Abstract: In this current contribution, authors are dedicated to
investigate influence of the crystal lamellae orientation on
electromechanical behaviors of relaxor ferroelectric Poly
(vinylidene fluoride –trifluoroethylene -chlorotrifluoroethylene)
(P(VDF-TrFE-CTFE)) films by control of polymer microstructure,
aiming to picture the full map of structure-property relationship. In
order to define their crystal orientation films, terpolymer films were
fabricated by solution-casting, stretching and hot-pressing process.
Differential scanning calorimetry, impedance analyzer, and tensile
strength techniques were employed to characterize crystallographic
parameters, dielectric permittivity, and elastic Young’s modulus
respectively. In addition, large electrical induced out-of-plane
electrostrictive strain was obtained by cantilever beam mode.
Consequently, as-casted pristine films exhibited surprisingly high
electrostrictive strain 0.1774% due to considerably small value of
elastic Young’s modulus although relatively low dielectric
permittivity. Such reasons contributed to large mechanical elastic
energy density. Instead, due to 2 folds increase of elastic Young’s
modulus and less than 50% augmentation of dielectric constant, fullycrystallized
film showed weak electrostrictive behavior and
mechanical energy density as well. And subjected to mechanical
stretching process, Film C exhibited stronger dielectric constant and
out-performed electrostrictive strain over Film B because edge-on
crystal lamellae orientation induced by uniaxially mechanical stretch.
Hot-press films were compared in term of cooling rate. Rather large
electrostrictive strain of 0.2788% for hot-pressed Film D in
quenching process was observed although its dielectric permittivity
equivalent to that of pristine as-casted Film A, showing highest
mechanical elastic energy density value of 359.5 J/m3. In hot-press
cooling process, dielectric permittivity of Film E saw values at 48.8
concomitant with ca.100% increase of Young’s modulus. Films with
intermediate mechanical energy density were obtained.
Abstract: Dietary cholesterol has elicited the most public
interest as it relates with coronary heart disease. Thus, humans have
been paying more attention to health, thereby reducing consumption
of cholesterol enriched food. Egg is considered as one of the major
sources of human dietary cholesterol. However, an alternative way to
reduce the potential cholesterolemic effect of eggs is to modify the
fatty acid composition of the yolk. The effect of palm oil (PO),
soybean oil (SO), sesame seed oil (SSO) and fish oil (FO)
supplementation in the diets of layers on egg yolk fatty acid,
cholesterol, egg production and egg quality parameters were
evaluated in a 42-day feeding trial. One hundred and five Isa Brown
laying hens of 34 weeks of age were randomly distributed into seven
groups of five replicates and three birds per replicate in a completely
randomized design. Seven corn-soybean basal diets (BD) were
formulated: BD+No oil (T1), BD+1.5% PO (T2), BD+1.5% SO (T3),
BD+1.5% SSO (T4), BD+1.5% FO (T5), BD+0.75% SO+0.75% FO
(T6) and BD+0.75% SSO+0.75% FO (T7). Five eggs were randomly
sampled at day 42 from each replicate to assay for the cholesterol,
fatty acid profile of egg yolk and egg quality assessment. Results
showed that there were no significant (P>0.05) differences observed
in production performance, egg cholesterol and egg quality
parameters except for yolk height, albumen height, yolk index, egg
shape index, haugh unit, and yolk colour. There were no significant
differences (P>0.05) observed in total cholesterol, high density
lipoprotein and low density lipoprotein levels of egg yolk across the
treatments. However, diets had effect (P
Abstract: Weak damping of low frequency oscillations is a frequent phenomenon in electrical power systems. These frequencies can be damped by power system stabilizers. Unified power flow controller (UPFC), as one of the most important FACTS devices, can be applied to increase the damping of power system oscillations and the more effect of this controller on increasing the damping of oscillations depends on its proper placement in power systems. In this paper, a technique based on controllability is proposed to select proper location of UPFC and the best input control signal in order to enhance damping of power oscillations. The effectiveness of the proposed technique is demonstrated in IEEE 9 bus power system.
Abstract: Advances in spatial and spectral resolution of satellite
images have led to tremendous growth in large image databases. The
data we acquire through satellites, radars, and sensors consists of
important geographical information that can be used for remote
sensing applications such as region planning, disaster management.
Spatial data classification and object recognition are important tasks
for many applications. However, classifying objects and identifying
them manually from images is a difficult task. Object recognition is
often considered as a classification problem, this task can be
performed using machine-learning techniques. Despite of many
machine-learning algorithms, the classification is done using
supervised classifiers such as Support Vector Machines (SVM) as the
area of interest is known. We proposed a classification method,
which considers neighboring pixels in a region for feature extraction
and it evaluates classifications precisely according to neighboring
classes for semantic interpretation of region of interest (ROI). A
dataset has been created for training and testing purpose; we
generated the attributes by considering pixel intensity values and
mean values of reflectance. We demonstrated the benefits of using
knowledge discovery and data-mining techniques, which can be on
image data for accurate information extraction and classification from
high spatial resolution remote sensing imagery.
Abstract: The nutritional composition and hypoglycaemic effect
of crackers produced from blend of sprouted pigeon pea, unripe
plantain and brewers’ spent grain and fed to Alloxan induced diabetic
rat was investigated. Crackers were produced from different blends of
sprouted pigeon pea, unripe plantain and brewers’ spent grain. The
crackers were evaluated for proximate composition, amino acid
profile and antinutritional factors. Blood glucose levels of normal and
diabetic rats fed with the control sample and different formulations of
cracker were measured. The protein content of the samples were
significantly different (p
Abstract: The purpose of this study is analyzing the relationship
between trust and social capital of people with using Social Network
Analysis. In this study, two aspects of social capital will be focused:
Bonding, homophilous social capital (BoSC), and Bridging,
heterophilous social capital (BrSC). These two aspects diverge each
other regarding to the social theories. The other concept of the study
is Trust (Tr), namely interpersonal trust, willing to ascribe good
intentions to and have confidence in the words and actions of other
people. In this study, the sample group, 61 people, was selected from
a private firm from the defense industry. The relation between
BoSC/BrSC and Tr is shown by using Social Network Analysis
(SNA) and statistical analysis with Likert type-questionnaire. The
results of the analysis show the Cronbach’s alpha value is 0.756 and
social capital values (BoSC/BrSC) is not correlated with Tr values of
the people.
Abstract: The occurrences of precipitation, also commonly
referred as rain, in the form of "convective" and "stratiform" have
been identified to exist worldwide. In this study, the radar return
echoes or known as reflectivity values acquired from radar scans
have been exploited in the process of classifying the type of rain
endured. The investigation use radar data from Malaysian
Meteorology Department (MMD). It is possible to discriminate the
types of rain experienced in tropical region by observing the vertical
characteristics of the rain structure. .Heavy rain in tropical region
profoundly affects radiowave signals, causing transmission
interference and signal fading. Required wireless system fade margin
depends on the type of rain. Information relating to the two
mentioned types of rain is critical for the system engineers and
researchers in their endeavour to improve the reliability of
communication links. This paper highlights the quantification of
percentage occurrences over one year period in 2009.
Abstract: In the present research, whole meal barley flour
(WBF) was supplemented with gelatinized corn flour (GCF) in 0 and
30%. Whole meal wheat flour (WWF) was mixed with defatted rice
bran (DRB) to produce 0, 20, 25, and 30% replacement levels.
Rheological properties of dough were studied. Thermal properties
and starch crystallinity of flours were evaluated. Flat bread, balady
bread and pie were prepared from the different flour blends. The
different bakeries were sensory evaluated. Color of raw materials and
crust of bakery products were determined. Nutrients contents of raw
flours and food products were assessed. Results showed that addition
of GCF to WBF increased the viscosity and falling number of the
produced dough. Water absorption, dough development time and
dough stability increased with increasing the level of DRB in dough
while, weakening and mixing tolerance index decreased.
Extensibility and energy decreased, while, resistance to extension
increased as DRB level increased. Gelatinized temperature of WWF,
WBF, GCF, and DRB were 13.26, 35.09, 28.33, and 39.63,
respectively. Starch crystallinity was affected when DRB was added
to WWF. The highest protein content was present in balady bread
made from 70% WWF and 30% DRB. The highest calcium,
phosphorus, and potassium levels were present in products made
from 100% WBF. Sensory attributes of the products were slightly
affected by adding DRB and GCF. Conclusion: Addition of DRB or
GCF to WWF or WBF, respectively affect the physical, chemical,
rheological and sensory properties of balady bread, flat bread, and pie
while improved their nutritive values.
Abstract: The strain intensity and redundant strains, dependent
in multistage TRIP wire drawing processes from values used single
partial reductions, should influence on the intensity of transformation
the retained austenite into martensite and thereby on mechanical
properties of drawn wires. The numerical analysis of drawing
processes with use of Drawing 2D programme, for steel wires made
from TRIP steel with 0,29% has been shown in the work. The change
of strain intensity εc and the values of redundant strain εxy, has been
determined for particular draws in dependence of used single partial
reductions.
Abstract: A broadband wire monopole antenna loaded by inhomogeneous stack of annular dielectric ring resonators (DRRs) is proposed. The proposed antenna exhibits a broad impedance bandwidth from 3 to 30 GHz. This is achieved by adding an external step matching network at the antenna feed point. The matching network is comprised of three annular DRRs possessing different permittivity values and sharing the same axial over a finite ground plane. The antenna performance is characterized using full-wave EM simulation. Compared to previous-reported wire antennas with improved bandwidth achieved by DRRs, the proposed topology provides relatively compact realization and superior broadband performance.
Abstract: In order to utilize results from global climate models,
dynamical and statistical downscaling techniques have been
developed. For dynamical downscaling, usually a limited area
numerical model is used, with associated high computational cost.
This research proposes dynamic equation for specific space-time
regional climate downscaling from the Educational Global Climate
Model (EdGCM) for Southeast Asia. The equation is for surface air
temperature. This equation provides downscaling values of surface
air temperature at any specific location and time without running a
regional climate model. In the proposed equations, surface air
temperature is approximated from ground temperature, sensible heat
flux and 2m wind speed. Results from the application of the equation
show that the errors from the proposed equations are less than the
errors for direct interpolation from EdGCM.
Abstract: A psychological contract is an agreement between the
employer and an employee that covers the parties’ informal and
frequently non-verbalized obligations and expectations towards each
other. The contract is a cognitive pattern-governing employee’s
behaviour in the organization. A gap between employee’s
expectations and the organizational reality may lead to difficult-to-solve
conflicts or cause the employee to modify their behaviour
towards organizational values and goals, if they are willing and ready
to verbalize their expectations. The article discusses psychological contracts in the financial
institutions in Poland. Its theoretical part outlines the types of
psychological contracts in organizations (relational, transactional, and
balanced) and shows the process of their verbalization. The purpose
of the article is to present how the type of the psychological contract
relates to employee’s readiness to verbalize it. The article ends with
conclusions arising from the study.
Abstract: The main purpose of this study is to assess the
sediment quality and potential ecological risk in marine sediments in
Gymea Bay located in south Sydney, Australia. A total of 32 surface
sediment samples were collected from the bay. Current track
trajectories and velocities have also been measured in the bay. The
resultant trace elements were compared with the adverse biological
effect values Effect Range Low (ERL) and Effect Range Median
(ERM) classifications. The results indicate that the average values of
chromium, arsenic, copper, zinc, and lead in surface sediments all
reveal low pollution levels and are below ERL and ERM values. The
highest concentrations of trace elements were found close to
discharge points and in the inner bay, and were linked with high
percentages of clay minerals, pyrite and organic matter, which can
play a significant role in trapping and accumulating these elements.
The lowest concentrations of trace elements were found to be on the
shoreline of the bay, which contained high percentages of sand
fractions. It is postulated that the fine particles and trace elements are
disturbed by currents and tides, then transported and deposited in
deeper areas. The current track velocities recorded in Gymea Bay had
the capability to transport fine particles and trace element pollution
within the bay. As a result, hydrodynamic measurements were able to
provide useful information and to help explain the distribution of
sedimentary particles and geochemical properties. This may lead to
knowledge transfer to other bay systems, including those in remote
areas. These activities can be conducted at a low cost, and are
therefore also transferrable to developing countries. The advent of
portable instruments to measure trace elements in the field has also
contributed to the development of these lower cost and easily applied
methodologies available for use in remote locations and low-cost
economies.
Abstract: Escherichia coli (E. coli) is the most isolated bacteria
from blood circulation of septicemic calves. Given the prevalence of
septicemia in animals and its economic importance in veterinary
practice, better understanding of changes in clinical signs following
disease, may contribute to early detection of disorder. The present
study has been carried out to detect changes of clinical signs in
induced sepsis in calves with E. coli. Colisepticemia has been
induced in 10 twenty-day old healthy Holstein- Frisian calves with
intravenous injection of 1.5 X 109 colony forming units (cfu) of
O111:H8 strain of E. coli. Clinical signs including rectal temperature,
heart rate, respiratory rate, shock, appetite, sucking reflex, feces
consistency, general behavior, dehydration and standing ability were
recorded in experimental calves during 24 hours after induction of
colisepticemia. Blood culture was also carried out from calves four
times during experiment. ANOVA with repeated measure is used to
see changes of calves’ clinical signs to experimental colisepticemia,
and values of P≤ 0.05 was considered statistically significant. Mean
values of rectal temperature and heart rate as well as median values
of respiratory rate, appetite, suckling reflex, standing ability and feces
consistency of experimental calves increased significantly during
study (P 0.05). The
results of present study showed that total score of clinical signs in
calves with experimental colisepticemia increased significantly,
although score of some clinical signs such as shock did not change
significantly.